Minimal power consumption is an increasing important feature receiving attention in newer computing platforms. Some aspects of the original Universal Serial Bus (USB) mass storage—e.g., Bulk-Only Transport (BOT) and USB Attached SCSI Protocol (UASP)—specifications tend to remain at odds with this trend. Overall power expenditure for a host system connected to a USB mass storage device may be improved with only a minor modification to these existing specifications.
Now, as part of the new USB 3.0 specification, a new feature has been added to improve bus utilization and power efficiency. Certain devices connected via USB 3.0 may now have the ability to notify the host of the device's readiness—in an asynchronous manner, and obviating the need for polling every device connected. In addition, modification of BOT and UASP specifications tends to eliminate the need for another type of polling which detects media state changes in devices with removable media.